Comparison of concrete shear wall and mega-braced steel frame regarding seismic performance

Abstract

The seismic behavior of two different lateral force resisting systems are compared regarding base shear, roof displacement and drift ratio through nonlinear static and dynamic analyses in the software SAP2000. The case study building is a 16-story commercial building located in Western Norway with shear wall core structure as the lateral force resisting system. During this report, the seismic behavior of this system is compared to the behavior of a mega-braced steel frame to evaluate whether this can be a beneficial solution for high-rise buildings in Norway. Further, the effect of adding friction dampers is investigated. It was found that the shear wall and MBF structure behaved differently during the seismic events. While the shear wall structure exerted largest base shear forces, the MBF clearly experienced larger roof deformations and story drifts. During the largest earthquake, the MBF also experienced failure in hinges of some braces, eventually resulting in initiation of collapse. The results of the nonlinear static analysis generally deviated from the direct integration and modal time-history analyses, which showed satisfying agreement in the obtained results.